Fine wire electrical connections in which insulated electrical wires are press-fitted in slots of electrical contacts are universally known as a technique for terminating insulated electrical wires without stripping insulation from the wires beforehand. However, in cases where extremely fine coil windings such as, e.g., fine wires having an AWG of 50 are terminated in such contacts, not only do the coil windings tend to break, but it is also extremely difficult to form narrow slots corresponding to the diameters of the coil windings into the contacts, into which the wires are press-fitted. Accordingly, one such previously described electrical connector 100 that is shown in FIGS. 11 and 12, is disclosed in Japanese Patent Publication No. 10-69929 for terminating fine electrical wires.
Electrical connector 100 comprises an insulating housing 150 having a cavity 152, and an electrical contact 110, which is inserted into cavity 152. Contact 110 has an external connecting section 112, which electrically connects with an external terminal (not shown), a press-fitting section 114, and an arcuate-shaped contact section 116 on which is located a serrated surface having contact points 116a that bite into an insulated electrical wire 3. A linear transition section 122 is disposed between the press-fitting section 114 and contact section 116 via a first bent section 124 and a second bent section 126. When the contact 110 is pressed downward by means of a tool 172 in engagement with the press-fitting section 114 so that the contact 110 is forcibly moved in a direction substantially perpendicular to the direction of insertion of the contact 110, the portion of the contact section 116 located in the vicinity of the second bent section 126, is driven against an inner tapered surface 160 of the cavity 152 as shown in FIG. 12. As a result, a secure electrical connection is obtained between the contact 110 and the insulated electrical wire 3.
In the contact 110 of electrical connector 100, a large amount of bending in the first bent section 124 and second bent section 126 takes place; accordingly, stress tends to concentrate in the bent sections. As a result, there is a danger that cracking will occur in the bent sections. Furthermore, since the contact 110 is a single integral member equipped with the connecting section 112 and contact section 116, the force applied to the connecting section 112 during the connection and disconnection of the external terminal with the connecting section 112, is transmitted directly to the contact section 116, thereby causing fluctuations in the contact points between the electrical wire 3 and contact section 116, so that there is a danger that the reliability of the electrical connection therebetween will be lowered. Furthermore, in the connected state shown in FIG. 12, portions of the contact 110 other than the contact section 116 lack flexibility; accordingly the dimensional tolerance in the horizontal direction between the first and second bent sections 124 and 126 is small. In response to this, strict dimensional control of the cavity 152 of the housing 150 in the horizontal direction is necessary; consequently, manufacture of the housing 150 is difficult.
International Publication No. W098/38698 discloses an electrical connector comprising a housing having first and second cavities that communicate with each other, a first contact member having a contact section that is press-fitted into the first cavity and an arcuate contact section that extends along a wire-engaging surface of the first cavity, and a second contact member that is press-fitted into the second cavity. When an insulated electrical wire is disposed between the wire-engaging surface and the arcuate contact section, and the second contact member is press-fitted into the second cavity, a pressing portion of the second contact member presses arcuate contact section toward the wire-engaging surface so that sawtooth-shaped serrations of the arcuate contact section make electrical connection with the insulated electrical wire.
The first contact member is not stabilized within the first cavity. Thus, during connection of a connecting section of the first contact member with a mating contact member or disconnection therefrom, the electrical connection between the arcuate contact section and the electrical wire can be disrupted.